The field of this invention is catheter assemblies and anchoring units therefor for use in intravenous feeding of medicinal fluids to the body.
In the field of medicine, percutaneous catheters are inserted through the skin for transferring medicinal fluid from a supply container to a blood vessel. Generally, such catheters are first inserted into a blood vessel and then connected to a supply container for the introduction of fluid by gravity flow or under positive pressure into the vessel. A well-known prior art intravenous includes a hollow, intravenous catheter portion having a tubular portion with a longitudinally extending lumen or wall portion therethrough. A hub portion is mounted onto one end of the catheter. The hub portion is adapted to be connected to a suitable transfer tube which extends to a supply container. This prior art catheter is inserted by means of a hollow needle or stylet which is initially mounted within the bore or lumen of the catheter. The sytlet terminates in a very sharp point so that the user is able to utilize the internally mounted stylet to penetrate the skin and locate the tubular portion within a blood vessel. Thereafter, the stylet is removed and the catheter hub is connected to the transfer tube connected to the supply container. Perhaps the most significant disadvantage of this type of prior art catheter results from the catheter occupying substantially the entire area of the blood vessel, thereby obstructing normal blood flow through the vessel. U.S. Pat. Nos. 3,727,613 3,225,762 and 3,776,239 are exemplary of catheter assemblies.
U.S. Pat. Nos. 3,835,863; 2,819,719; 2,790,442; and, 2,624,341 disclose drainage devices that are surgically inserted into the body and thereafter removed. Such catheters are principally used as drainage devices only and differ distinctly from the percutaneous-type catheters which must be inserted through the skin. U.S. Pat. No. 2,042,900 discloses a catheter assembly which is utilized in embalming.
Another very practical problem with catheters such as disclosed in the Guttman patent is maintaining the inserted catheter in a stable position; for catheters such as those disclosed in the Guttman patent are subject to movement or "plowing" within the blood vessel due to movement of the patient or equipment. Such movement or plowing of the catheter causes extreme irritation to the patient and may actually permanently damage either the blood vessel or the skin surrounding the catheter. Various attempts have been made to suitably anchor a catheter against such undesired movement. For example, U.S. Pat. No. 3,973,565 of Steer discloses a cannula which is fitted with laterally extending wings and a flexible sheet of material having an adhesive surface which is fixed to the wings and is capable of folding forwardly beyond the wings to engage the skin of the patient to hold the cannula and the remainder of the device in position. U.S. Pat. No. 3,064,648 of Bujan discloses an anchor mounted onto an intravenous needle assembly which includes opposing wing strips of relatively flexible material formed integrally with a mounting tubing; the wing strips are pivotally connected to the mounting tubing by a section of thinner or weaker material located at the point of connection of the strips to the mounting tubing. Other U.S. patents of interest include U.S. Pat. Nos. 3,920,001; 3,906,946; 3,766,915; and, 3,769,975.